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Nudibranchs have a mostly carnivorous diet, and they prey on a wide variety of other animal taxa. Many species, mainly belonging to the Cladobranchia suborder, feed on cnidarians, including member of the class Hydrozoa. Several hydrozoan species display a symbiotic lifestyle, being associated with other benthic invertebrates, including for instance bryozoans, corals, octocorals, and sponges. In our knowledge, no record of nudibranch predation on symbiotic hydrozoans has been reported so far, possibly thanks to the protective action by the host towards its symbiotic hydrozoan. Here, we show the unexpected case of a nudibranch belonging to the recently described species Sakuraeolis marhe (Fernández-Simón and Moles, 2023) feeding on Zanclea sp. 2, a hydrozoan associated with the cheilostome bryozoan Celleporaria sp. This trophic association is confirmed by the presence and storage of the nematocysts into the nudibranch cnidosacs. Moreover, the nudibranch appears to selectively store mostly a single type of nematocyst, that is large size stenotele. The observation here reported represents the first well-documented record of a nudibranch feeding on a symbiotic hydrozoan and the first confirmed case of predation on Zanclea polyps. Moreover, we provide additional genetic information and the first description of the internal anatomy of S. marhe.

I licheni – essendo sistemi autosufficienti, mutualistici e simbiotici – ospitano una molteplicità di microrganismi (procarioti, microalghe e microfunghi), la cui biodiversità e ruolo nella simbiosi è ancora ampiamente sconosciuta. Fino ad oggi, pochi studi si sono concentrati sulla diversità complessiva dei funghi associati ai licheni che costituisce il micobioma lichenico. In questa ricerca, ho caratterizzato la diversità del micobioma di due licheni epilitici e cosmopoliti, i.e. Rhizoplaca melanophthalma e Tephromela atra, che sono stati scelti come organismi studio. Avendo campioni di licheni provenienti da tutto il loro areale geografico è stato possibile per la prima volta analizzare il micobioma su scala globale. Per fare questo è stato eseguito sia l’approccio di coltura-dipendente che quello di metabarcoding del DNA ambientale (eDNA). L’obiettivi erano i) caratterizzare possibili comunità fungine che si mantengono stabili per una data specie di lichene e verificare se una parte di questa comunità fosse condivisa tra i due organismi studio; ii) capire se le condizioni ambientali influenzano la composizione e specificità del micobioma dei licheni. Utilizzando l’approccio di coltura-dipendente, ho isolato e identificato sulla base di dati morfologici e genetici, 76 lieviti basidiomiceti (appartenenti alle classi Agaricostilbomycetes, Cystobasidiomycetes, Microbotryomycetes, Tremellomycetes and Ustilaginomycetes) e 131 funghi ascomiceti (appartenenti alle classi Eurotiomycetes, Dothideomycetes e Sordariomycetes). Inoltre, per i funghi ascomiceti ho descritto due nuove specie nell’ordine Chaetothyriales. La maggior parte dei funghi isolati, sia ascomiceti che basidiomiceti, erano già stati precedentemente descritti in licheni, o risultavano filogeneticamente vicini a specie che solitamente occupano altre nicchie ecologiche (i.e. piante, rocce e suolo) e che hanno evoluto stili di vita diversi (patogeni di piante, opportunisti o saprotrofi). Tramite il metabarcoding del DNA, prima di tutto ho disegnato e testato un set di cosiddetti ‘blocking primers’ i quali riducono specificatamente l’amplificazione dei micobionti di R. melanophthalma e T. atra e di conseguenza permettono l’identificazione di tutti gli altri funghi presenti nei licheni. Tuttavia, questo esperimento non ha funzionato e ho eseguito l’approccio di metabarcoding senza utilizzarli. Il confronto della comunità fungine ha mostrato una bassa diversità per i singoli talli con la comparsa di pochi ascomiceti costantemente presenti in entrambe le due specie di licheni, la maggior parte appartenenti all’ordine Chaetothyriales, Capnodiales and Helotiales. I basidiomiceti rappresentano solo il 7-14% delle sequenze, e la maggioranza appartiene all’ordine Tremellales. Le condizioni ambientali, soprattutto le più rigide (e.g. elevate altitudini) e isolamento geografico sono i principali fattori che influiscono sulla composizione del micobioma dei licheni, mentre il micobionte sembra avere un ruolo minore. In R. melanophthalma e T. atra non è stata identificata una comunità fungina stabile e specifica poiché soli pochi taxa sono presenti nei licheni con bassa frequenza e nessuno di questi è presente in entrambe le specie studio. Infine, ho confrontato la diversità fungina ottenuta applicando l’approccio di metabarcoding con quella ottenuta con metodo di coltura-dipendente, per capire quale frazione del micobioma è identificabile utilizzando diversi approcci. Anche se il DNA metabarcoding permette di catturare una maggiore diversità, è interessante notare come alcune specie di funghi che sono cresciuti in coltura non è stata identificata dalle analisi di metabarcoding. Per concludere, l’approccio di coltura-dipendente e il DNA metabarcoding integrandosi l’uno con l’altro hanno permesso di ottenere una visione completa della diversità del micobioma in R. melanophthalma e T. atra. Lichens – as self-sustaining, mutualistic and symbiotic systems – house a multiplicity of microorganisms (prokaryotes, microalgae and microfungi), whose biodiversity and roles in the symbioses are still largely unknown. Until recently, only a few studies focused on the overall diversity of the lichen-associated fungi which constitute the lichen mycobiome. In this research, I characterized the diversity of the lichen mycobiome in two cosmopolitan, epilithic lichens, i.e. Rhizoplaca melanophthalma and Tephromela atra, that were chosen as study organisms. Their mycobiomes were investigated for the first time at a global scale, as lichen samples were collected across their entire geographic range and both a culture-dependent and environmental DNA (eDNA) metabarcoding approaches were performed. I aimed at i) characterizing if any stable ‘core mycobiome’ can be detected for each lichen species and if a shared mycobiome exists; ii) understanding the role of the environmental conditions in determining the lichen mycobiome composition. By culture-dependent approach, I isolated and identified, using an integrated approach based on morphological and phylogenetic data, 76 basidiomycete yeasts (belonging to the five classes Agaricostilbomycetes, Cystobasidiomycetes, Microbotryomycetes, Tremellomycetes and Ustilaginomycetes) and 131 ascomycetes fungi (belonging to the three classes Eurotiomycetes, Dothideomycetes and Sordariomycetes). Furthermore, within the ascomycetes fungi I identified two new lineages in Chaetothyriales. Most of the isolated fungi, either the ascomycetes and basidiomycetes, have been previously found in lichens, or resulted to be taxa closely related to species which usually occupy other ecological niches (i.e. plants, rocks and soil) and which adopt different lifestyles (i.e. plant pathogens, opportunists and saprotrophs). By DNA metabarcoding, I first tried to design and test a set of blocking primers, which were specifically designed to reduce the amplification of R. melanophthalma and T. atra mycobionts and to enhance the amplification of all the other fungi present within the lichen thalli. However, these primers did not prevent the amplification of the mycobionts and I carried out the metabarcoding approach without using them. The comparison of the fungal communities highlighted low diversity within single thalli with the presence of few ascomycetes consistently present in both lichen species, mostly belonging to Chaetothyriales, Capnodiales and Helotiales. Basidiomycetes account only for 7-14% of the sequences, mostly from Tremellales. The environmental conditions, especially when harsh (e.g. extreme elevation) and the geographic isolation possibly played the main role in shaping the mycobiome composition, however also the lichen host seemed to influence the mycobiome community, though in a lesser extent. A stable species-specific core mycobiome was hardly identifiable both in R. melanophthalma and T. atra as most of the mycobiome taxa were present with low frequency of occurrence and no taxon was ubiquitously present in neither lichen. I also compared the fungal diversity detected by DNA metabarcoding with the one obtained by the culture-dependent approach, to understand which fraction of the mycobiome was only detected either by culture isolation or by eDNA analyses. Even if DNA metabarcoding described most of the diversity of the lichen mycobiome, and many of the metabarcoded taxa were also isolated in culture, surprisingly there were some fungal species which grew in culture but were not detected by the metabarcoding analysis. In conclusion, both the culture-dependent and the DNA metabarcoding approaches well complemented each other and allowed to obtain a fairly complete estimation of the global lichen mycobiome diversity in R. melanophthalma and T. atra.

Rocks are among the oldest terrestrial niches hosting a multiplicity of life forms, of which diversity has been only partially uncovered. Endolithic metacommunities comprise all major groups of microorganisms, such as chemo-organotrophic, chemo-lithotrophic and phototrophic, represented by bacteria, microalgae and microfungi. Their diversity is often difficult to describe and may remain underestimated. Furthermore, knowledge about the diversity of microorganisms colonizing rocks in peculiar niches is even poorer due to the difficulty to retrieve environmental specimens. Here, we report the phylogenetic and phenotypic characterization of a few endolithic fungi and algae isolated from rock fragments collected at high elevation, i.e., on the top of two mountains over 6000 m altitude, Muztagh Ata (China) and Cerro Mercendario (Argentina). The identity of the strains was confirmed by sequencing the nuclear ITS and LSU, the plastidial rbcL loci and by morphological analysis. Three fungal strains belonging to the class Dothideomycetes and one algal strain belonging to the genus Trebouxia were isolated from Muztagh Ata, while six fungal strains belonging to the order Chaetothyriales and four algal strains belonging to the genus Myrmecia were isolated from Cerro Mercedario. The detected species diversity is discussed in an evolutionary and ecological context.

Mutualisms are foundational components of ecosystems with the capacity to generate biodiversity through adaptation and coevolution and give rise to essential services such as pollination and seed dispersal. To understand how mutualistic interactions shape communities and ecosystems, we must identify the mechanisms that underlie their functioning. One mechanism that may drive mutualisms to vary in space and time is the unique behavioral types, or personalities, of the individuals involved. Here, our goal was to examine interindividual variation in the seed dispersal mutualism and identify the role that different personalities play. In a field experiment, we observed individual deer mice (Peromyscus maniculatus) with known personality traits predating and dispersing seeds in a natural environment and classified all observed interactions made by individuals as either positive or negative. We then scored mice on a continuum from antagonistic to mutualistic and found that within a population of scatter hoarders, some individuals are more mutualistic than others and that one factor driving this distinction is animal personality. Through this empirical work, we provide a conceptual advancement to the study of mutualism by integrating it with the study of intraspecific behavioral variation. These findings indicate that animal personality is a previously overlooked mechanism generating context dependence in plant–animal interactions and suggest that behavioral diversity may have important consequences for the functioning of mutualisms.

Lichens are well-known examples of complex symbiotic associations between organisms from different Kingdoms. Microfungi in particular, establish diverse associations with the hosting lichen thallus, as species-specific parasites or transient co-inhabitants. The whole community of lichen-associated fungi constitute the 'lichen mycobiome' comprising both ascomycetes and basidiomycetes, including filamentous and yeast taxa. Metabarcoding results and microscopy analyses show that in some thalli, basidiomycetes are frequent lichen-associated fungi but still only a few species could be axenically isolated and morphologically characterized. Within a broad project aiming at characterizing the mycobiome diversity by culture-dependent and independent approaches in two lichen species selected as reference models - Rhizoplaca melanophthalma and Tephromela atra, we succeed in isolating and culturing 76 new strains of basidiomycetous yeasts. The lichen thalli were collected in different mountain regions worldwide and at relatively high elevation. The yeast strains were isolated on different growth media and were studied for their morphological and genetic diversity. Nuclear internal transcribed spacer (ITS) and ribosomal large subunit (LSU) sequence analyses identified them to belong to ten families within the orders Agaricostilbomycetes, Cystobasidiomycetes, Microbotryomycetes, Tremellomycetes and Ustilaginomycetes. The yeasts here detected showed patterns of host-preference in a few cases and they are potentially related to the ecological conditions.

Coral reefs are known to be among the most biodiverse marine ecosystems and one of the richest in terms of associations and species interactions, especially those involving invertebrates such as corals and sponges. Despite that, our knowledge about cryptic fauna and their ecological role remains remarkably scarce. This study aimed to address this gap by defining for the first time the spatial ecology of the association between the epibiont hydrozoan Nemalecium lighti and the Porifera community of shallow coral reef systems at Bonaire. In particular, the host range, prevalence, and distribution of the association were examined in relation to different sites, depths, and dimensions of the sponge hosts. We report Nemalecium lighti to be in association with 9 out of 16 genera of sponges encountered and 15 out of 16 of the dive sites examined. The prevalence of the hydroid–sponge association in Bonaire reef was 6.55%, with a maximum value of over 30%. This hydrozoan has been found to be a generalist symbiont, displaying a strong preference for sponges of the genus Aplysina, with no significant preference in relation to depth. On the contrary, the size of the host appeared to influence the prevalence of association, with large tubular sponges found to be the preferred host. Although further studies are needed to better understand the biological and ecological reason for these results, this study improved our knowledge of Bonaire’s coral reef cryptofauna diversity and its interspecific associations.

Lichens are classic models of symbiosis, and one of the most frequent nutritional modes among fungi. The ecologically and geographically widespread lichen-forming algal (LFA) genus Trebouxia is one of the best-studied groups of LFA and associates with over 7000 fungal species. Despite its importance, little is known about its diversification. We synthesized twenty years of publicly available data by characterizing the ecological preferences of this group and testing for time-variant shifts in climatic regimes over a distribution of trees. We found evidence for limited shifts among regimes, but that disparate lineages convergently evolved similar ecological tolerances. Early Trebouxia lineages were largely forest specialists or habitat generalists that occupied a regime whose extant members occur in moderate climates. Trebouxia then convergently diversified in non-forested habitats and expanded into regimes whose modern representatives occupy wet-warm and cool-dry climates. We rejected models in which climatic diversification slowed through time, suggesting climatic diversification is inconsistent with that expected under an adaptive radiation. In addition, we found that climatic and vegetative regime shifts broadly coincided with the evolution of biomes and associated or similar taxa. Together, our work illustrates how this keystone symbiont from an iconic symbiosis evolved to occupy diverse habitats across the globe.

In this work we describe Stagonosporopsis rhizophilae sp. nov. (Didymellaceae, Pleosporales, Ascomycota), a new species isolated from the rhizospheric soil of Populus deltoides Marsh. Phylogenetic analyses based on combined multilocus sequences of internal transcribed spacers (ITS: ITS1, 5.8S, ITS2), and partial sequences of the large subunit 28S nrDNA region (LSU), β-tubulin (TUB), and RNA Polymerase II second-largest subunit (RPB2) clearly place this species within the genus Stagonosporopsis but distinguishes it from all known and closely related species such as S. nemophilae. Stagonosporopsis rhizophilae sp. nov. can also be differentiated from S. nemophilae by morphological characters and by the negative response of the NaOH spot test for the production of metabolite E.

Rapid warming and sea-level rise are predicted to be major driving forces in shaping coastal ecosystems and their services in the next century. Though forecasts of the multiple and complex effects of temperature and sea-level rise on ecological interactions suggest negative impacts on parasite diversity, the effect of long term climate change on parasite dynamics is complex and unresolved. Digenean trematodes are complex life cycle parasites that can induce characteristic traces on their bivalve hosts and hold potential to infer parasite host-dynamics through time and space. Previous work has demonstrated a consistent association between sea level rise and increasing prevalence of trematode traces, but a number of fundamental questions remain unanswered about this paleoecological proxy. Here we examine the relationships of host size, shape, and functional morphology with parasite prevalence and abundance, how parasites are distributed across hosts, and how all of these relationships vary through time, using the bivalve Chamelea gallina from a Holocene shallow marine succession in the Po coastal plain. Trematode prevalence increased and decreased in association with the transition from a wave-influenced estuarine system to a wave-dominated deltaic setting. Prevalence and abundance of trematode pits are associated with large host body size, reflecting ontogenetic accumulation of parasites, but temporal trends in median host size do not explain prevalence trends. Ongoing work will test the roles of temperature, salinity, and nutrient availability on trematode parasitism. Parasitized bivalves in one sample were shallower burrowers than their non-parasitized counterparts, suggesting that hosts of trematodes can be more susceptible to their predators, though the effect is ephemeral. Like in living parasite-host systems, trematode-induced malformations are strongly aggregated among hosts, wherein most host individuals harbor very few parasites while a few hosts have many. We interpret trace aggregation to support the assumption that traces are a reliable proxy for trematode parasitism in the fossil record.

Green fluorescence is a common phenomenon in marine invertebrates and is caused by green fluorescent proteins. Many hydrozoan species display fluorescence in their polyps and/or medusa stages, and in a few cases patterns of green fluorescence have been demonstrated to differ between closely related species. Hydrozoans are often characterized by the presence of cryptic species, due to the paucity of available morphological diagnostic characters. Zanclea species are not an exception, showing high genetic divergence compared to a uniform morphology. In this work, the presence of green fluorescence and the morpho-molecular diversity of six coral- and bryozoan-associated Zanclea species from the Maldivian coral reefs were investigated. Specifically, the presence of green fluorescence in polyps and newly released medusae was explored, the general morphology, as well as the cnidome and the interaction with the hosts, were characterized, and the 16S rRNA region was sequenced and analyzed. Overall, Zanclea species showed a similar morphology, with little differences in the general morphological features and in the cnidome. Three of the analyzed species did not show any fluorescence in both life stages. Three other Zanclea species, including two coral-associated cryptic species, were distinguished by species-specific fluorescence patterns in the medusae. Altogether, the results confirmed the morphological similarity despite high genetic divergence in Zanclea species and indicated that fluorescence patterns may be a promising tool in further discriminating closely related and cryptic species. Therefore, the assessment of fluorescence at a large scale in the whole Zancleidae family may be useful to shed light on the diversity of this enigmatic taxon.

Lichens provide valuable systems for studying symbiotic interactions. In lichens, these interactions are frequently described in terms of availability, selectivity and specificity of the mycobionts and photobionts towards one another. The lichen-forming, green algal genus Trebouxia Puymaly is among the most widespread photobiont, associating with a broad range of lichen-forming fungi. To date, 29 species have been described, but studies consistently indicate that the vast majority of species-level lineages still lack formal description, and new, previously unrecognized lineages are frequently reported. To reappraise the diversity and the evolutionary relationships of species-level lineages in Trebouxia, we assembled DNA sequence data from over 1600 specimens, compiled from a range of sequences from previously published studies, axenic algal cultures, and lichens collected from poorly sampled regions. From these samples, we selected representatives of the currently known genetic diversity in the lichenized Trebouxia and inferred a phylogeny from multi-locus sequence data (ITS, rbcL, cox2). We demonstrate that the current formally described species woefully underrepresent overall species-level diversity in this important lichen-forming algal genus. We anticipate that an integrative taxonomic approach, incorporating morphological and physiological data from axenic cultures with genetic data, will be required to establish a robust, comprehensive taxonomy for Trebouxia. The data presented here provide an important impetus and reference dataset for more reliably characterizing diversity in lichenized algae and in using lichens to investigate the evolution of symbioses and holobionts.

[EN] The identity of the dominant root-associated microbial symbionts in a forest determines the ability of trees to access limiting nutrients from atmospheric or soil pools, sequester carbon and withstand the effects of climate change. Characterizing the global distribution of these symbioses and identifying the factors that control this distribution are thus integral to understanding the present and future functioning of forest ecosystems. Here we generate a spatially explicit global map of the symbiotic status of forests, using a database of over 1.1 million forest inventory plots that collectively contain over 28,000 tree species. Our analyses indicate that climate variables—in particular, climatically controlled variation in the rate of decomposition—are the primary drivers of the global distribution of major symbioses. We estimate that ectomycorrhizal trees, which represent only 2% of all plant species, constitute approximately 60% of tree stems on Earth. Ectomycorrhizal symbiosis dominates forests in which seasonally cold and dry climates inhibit decomposition, and is the predominant form of symbiosis at high latitudes and elevation. By contrast, arbuscular mycorrhizal trees dominate in aseasonal, warm tropical forests, and occur with ectomycorrhizal trees in temperate biomes in which seasonally warm-and-wet climates enhance decomposition. Continental transitions between forests dominated by ectomycorrhizal or arbuscular mycorrhizal trees occur relatively abruptly along climate-driven decomposition gradients; these transitions are probably caused by positive feedback effects between plants and microorganisms. Symbiotic nitrogen fixers—which are insensitive to climatic controls on decomposition (compared with mycorrhizal fungi)—are most abundant in arid biomes with alkaline soils and high maximum temperatures. The climatically driven global symbiosis gradient that we document provides a spatially explicit quantitative understanding of microbial symbioses at the global scale, and demonstrates the critical role of microbial mutualisms in shaping the distribution of plant species., This work was made possible by the Global Forest Biodiversity Database, which represents the work of over 200 independent investigators and their public and private funding agencies (see Supplementary Acknowledgements), Supplementary information is available for this paper at https://doi.org/10.1038/s41586-019-1128-0.

Symbiotic relationships on coral reefs involving benthic hosts other than scleractinian corals have been poorly investigated. The hydroid Pteroclava krempfi is a widespread species known to be mainly associated with alcyonacean octocorals in the Indo-Pacific. In the present study, P. krempfi was discovered in association with octocorals of the genus Antillogorgia (Gorgoniidae) at two localities in the Caribbean Sea (St. Eustatius in the eastern Caribbean and Bocas del Toro in the western part), updating its host range with an additional genus and family. The Caribbean specimens showed no morphological differences and the shape of their polyps was consistent with the original P. krempfi description. A multi-locus phylogeny reconstruction of the P. krempfi species complex based on both mitochondrial and nuclear loci revealed three separate molecular clades. Two of them were composed of P. krempfi associated with the families Plexauridae and Alcyoniidae from the Maldives, whereas a new highly supported molecular lineage included all Caribbean specimens of P. krempfi associated with the family Gorgoniidae. These three divergent molecular clades represent distinct cryptic taxa within the P. krempfi species complex, in which the main interspecific difference consists of their host families.

This article seeks to present a summary of knowledge and thus improve awareness of microplastic impacts on corals. Recent research suggests that microplastics have a variety of species-specific impacts. Among them, a reduced growth, a substantial decrease of detoxifying and immunity enzymes, an increase in antioxidant enzyme activity, high production of mucus, reduction of fitness, and negative effects on coral-Symbiodiniaceae relationships have been highlighted in recent papers. In addition to this, tissue necrosis, lower fertilization success, alteration of metabolite profiles, energetic costs, decreased skeletal growth and calcification, and coral bleaching have been observed under significant concentrations of microplastics. Furthermore, impairment of feeding performance and food intake, changes in photosynthetic performance and increased exposure to contaminants, pathogens and other harmful compounds have also been found. In conclusion, microplastics may cause a plethora of impacts on corals in shallow, mesophotic, and deep-sea zones at different latitudes; underlining an emerging threat globally. This study is part of the project “I-Plastics: Dispersion and impacts of micro- and nano-plastics in the tropical and temperate oceans: from regional land-ocean interface to open ocean”. The authors would like to acknowledge the funding from the JPI Oceans International Consortium/CONFAP. We thank to Conselho Nacional de Desenvolvimento Científico e Tecnológico – CNPq (Research Productivity Fellowship, 307061/2017), CAPES-PRINT, INCT AmbTropic and the Fundação Cearense de Apoio ao Desenvolvimento Científico e Tecnológico - FUNCAP (Chief Scientist Program) for the financial support. ALA is supported by Science Foundation Ireland and the Marine Institute under the Investigators Programme Grant Number SFI/15/IA/3100 co-funded under the European Regional Development Fund 2014-2020. This paper from our research group (number 7) celebrates the beginning of the United Nations (UN) Decade of the Ocean Science for Sustainable Development (2021−2030). We hope that this decade will provide a ‘once in a lifetime’ global opportunity to create a new science-based foundation to society, across the science-policy interface, to strengthen the management of our oceans and coasts for the benefit of humankind and all marine species. peer-reviewed 2022-11-01

AimThe aim of the study was to assess the diversity of algal symbionts of the family Symbiodiniaceae associated with the coral genus Porites in the Red Sea, and to test for host‐specificity and environmental variables driving biogeographical patterns of algal symbiont distribution.LocationSaudi Arabian Red Sea.TaxonEndosymbiotic dinoflagellates of the family Symbiodiniaceae in association with the reef‐building coral genus Porites.MethodsEighty Porites coral specimens were collected along the Saudi Arabian Red Sea coast. Species boundaries were assessed morphologically and genetically (putative Control Region – mtCR; ITS region – ITS). Community composition of symbiotic dinoflagellates of the family Symbiodiniaceae was also assessed. Using the ITS2 marker with the SymPortal framework, Symbiodiniaceae data at the genus, majority ITS2 sequence and ITS2 type profile were used to assess symbiont diversity and distribution patterns. These were analysed in relation to coral host diversity, geographic location and environmental variables.ResultsAmong the 80 Porites samples, 10 morphologies were identified. These corals were clustered into five lineages (clades I–V) by each of the markers independently. Clades I, II and III each comprised of a single Porites morphology, while clades IV and V contained up to five distinct morphologies. The diversity of Symbiodiniaceae associated with Porites was high and latitudinal differentiation was observed. In particular, a shift from a Cladocopium‐dominated to a Durusdinium‐dominated community was found along the north–south gradient. Symbiont diversity showed the patterns of geographic‐specific association at Symbiodiniaceae genus, majority ITS2 sequence and ITS2 type profile level. Specific associations with host genotypes (but not morphological species) were also recovered when considering Symbiodiniaceae majority ITS2 sequence and ITS2 type profiles.Main conclusionsThis study provides the first large‐scale molecular characterization of Symbiodiniaceae communities associated with Porites corals from the Saudi Arabian Red Sea. The use of intragenomic diversity data enabled the resolution of host‐symbiont specificity and biogeographical patterns of distribution, previously unachievable with the ITS2 marker alone. Finally, correlation among symbiont diversity and Red Sea environmental gradients was documented. published

Aplysina aerophoba is an emerging model marine sponge, with a well-characterized microbial community in terms of diversity and structure. However, little is known about the expressed functional capabilities of its associated microbes. Here, we present the first metaproteomics-based study of the microbiome of A. aerophoba. We found that transport and degradation of halogenated and chloroaromatic compounds are common active processes in the sponge microbiomes. Our data further reveal that the highest number of proteins were affiliated to a sponge-associated Tectomicrobium, presumably from the family Entotheonellaceae, as well as to the well-known symbiont “Candidatus Synechococcus spongiarium”, suggesting a high metabolic activity of these two microorganisms in situ. Evidence for nitric oxide (NO) conversion to nitrous oxide was consistently observed for Tectomicrobia across replicates, by production of the NorQ protein. Moreover, we found a potential energy-yielding pathway through CO oxidation by putative Chloroflexi bacteria. Finally, we observed expression of enzymes that may be involved in the transformation of chitin, glycoproteins, glycolipids and glucans into smaller molecules, consistent with glycosyl hydrolases predicted from analyses of the genomes of Poribacteria sponge symbionts. Thus, this study provides crucial links between expressed proteins and specific members of the A. aerophoba microbiome.

Background The emerging roles of rhizobacteria in improving plant nutrition and stress protection have great potential for sustainable use in saline soils. We evaluated the function of the salt-tolerant strain Azotobacter chroococcum 76A as stress protectant in an important horticultural crop, tomato. Specifically we hypothesized that treatment of tomato plants with A. chroococcum 76A could improve plant performance under salinity stress and sub-optimal nutrient regimen. Results Inoculation of Micro Tom tomato plants with A. chroococcum 76A increased numerous growth parameters and also conferred protective effects under both moderate (50 mM NaCl) and severe (100 mM NaCl) salt stresses. These benefits were mostly observed under reduced nutrient regimen and were less appreciable in optimal nitrogen conditions. Therefore, the efficiency of A. chroococcum 76A was found to be dependent on the nutrient status of the rhizosphere. The expression profiles of LEA genes indicated that A. chroococcum 76A treated plants were more responsive to stress stimuli when compared to untreated controls. However, transcript levels of key nitrogen assimilation genes revealed that the optimal nitrogen regimen, in combination with the strain A. chroococcum 76A, may have saturated plant’s ability to assimilate nitrogen. Conclusions Roots inoculation with A. chroococcum 76A tomato promoted tomato plant growth, stress tolerance and nutrient assimilation efficiency under moderate and severe salinity. Inoculation with beneficial bacteria such as A. chroococcum 76A may be an ideal solution for low-input systems, where environmental constraints and limited chemical fertilization may affect the potential yield.

The phylum Cnidaria is an ancient branch in the tree of metazoans. Several species exert a remarkable longevity, suggesting the existence of a developed and consistent defense mechanism of the innate immunity capable to overcome the potential repeated exposure to microbial pathogenic agents. Increasing evidence indicates that the innate immune system in Cnidarians is not only involved in the disruption of harmful microorganisms, but also is crucial in structuring tissue-associated microbial communities that are essential components of the Cnidarian holobiont and useful to the animal’s health for several functions, including metabolism, immune defense, development, and behavior. Sometimes, the shifts in the normal microbiota may be used as “early” bio-indicators of both environmental changes and/or animal disease. Here the Cnidarians relationships with microbial communities and the potential biotechnological applications are summarized and discussed.

Lichen symbioses develop long-living thallus structures even in the harshest environments on Earth. These structures are also habitats for many other microscopic organisms, including other fungi, which vary in their specificity and interaction with the whole symbiotic system. This contribution reviews the recent progress regarding the understanding of the lichen-inhabiting fungi that are achieved by multiphasic approaches (culturing, microscopy, and sequencing). The lichen mycobiome comprises a more or less specific pool of species that can develop symptoms on their hosts, a generalist environmental pool, and a pool of transient species. Typically, the fungal classes Dothideomycetes, Eurotiomycetes, Leotiomycetes, Sordariomycetes, and Tremellomycetes predominate the associated fungal communities. While symptomatic lichenicolous fungi belong to lichen-forming lineages, many of the other fungi that are found have close relatives that are known from different ecological niches, including both plant and animal pathogens, and rock colonizers. A significant fraction of yet unnamed melanized (‘black’) fungi belong to the classes Chaethothyriomycetes and Dothideomycetes. These lineages tolerate the stressful conditions and harsh environments that affect their hosts, and therefore are interpreted as extremotolerant fungi. Some of these taxa can also form lichen-like associations with the algae of the lichen system when they are enforced to symbiosis by co-culturing assays.

A comparative study of isolated vs. lichenized Trebouxia sp. showed that lichenization does not influence the survival capability of the alga to the photo-oxidative stress derived from prolonged desiccation. Coccoid algae in the Trebouxia genus are the most common photobionts of chlorolichens but are only sporadically found in soil or bark outside of a lichen. They all appear to be desiccation tolerant, i.e. they can survive drying to water contents of below 10 %. However, little is known about their longevity in the dry state and to which extent lichenization can influence it. Here, we studied the longevity in the dry state of the lichenized alga (LT) Trebouxia sp. in the lichen Parmotrema perlatum, in comparison with axenically grown cultures (CT) isolated from the same lichen. We report on chlorophyll fluorescence emission and reactive oxygen species (ROS) production before desiccation, after 15–45 days in the dry state under different combinations of light and air humidity and after recovery for 1 or 3 days in fully hydrated conditions. Both the CT and the LT were able to withstand desiccation under high light (120 µmol photons m−2 s−1 for 14 h per day), but upon recovery after 45 days in the dry state the performance of the CT was better than that of the LT. By contrast, the quenching of excess light energy was more efficient in the LT, at high relative humidities especially. ROS production in the LT was influenced mostly by light exposure, whereas the CT showed an oxidative burst independent of the light conditions. Although lichenization provides benefits that are essential for the survival of the photobiont in high-light habitats, Trebouxia sp. can withstand protracted periods of photo-oxidative stress even outside of a lichen thallus.

Mushroom corals (Anthozoa: Scleractinia: Fungiidae) have been well documented as hosts of a rich associated fauna, but no records involving the symbiotic hydrozoan genus Zanclea (Hydrozoa: Capitata: Zancleidae) are known. These small (~1 mm long), coral-associated hydroids have only been reported from associations involving 23 non-fungiid scleractinian host species in the Indo-Pacific. Since both groups, Fungiidae and coral-dwelling Zanclea hydroids, are known to occur on Indo-Pacific coral reefs, it was unclear why no mushroom coral hosts were known. Therefore, a survey in the Maldives was performed aiming at the discovery of Zanclea–Fungiidae associations. Subsequently, 10 new host species were discovered and the number of recorded coral host genera increased from 17 to 24, taking recent taxonomic revisions into account. These findings indicate that the coral-associated biodiversity is still insufficiently explored.

Symbiotic relationships benefit organisms in utilization of new niches. In parasitoid wasps, symbiotic viruses and venom that are injected together with wasp eggs into the host caterpillar suppress immune responses of the host and enhance parasitoid survival. We found that the virus also has negative effects on offspring survival when placing these interactions in a community context. The virus and venom drive a chain of interactions that includes the herbivore and its food plant and attracts the hyperparasitoid enemies of the parasitoid. Our results shed new light on the importance of symbionts associated with their host in driving ecological interactions and highlight the intricacy of how multispecies interactions are reflected in adaptations of individual species such as the host-finding behavior of hyperparasitoids.Symbiotic relationships may provide organisms with key innovations that aid in the establishment of new niches. For example, during oviposition, some species of parasitoid wasps, whose larvae develop inside the bodies of other insects, inject polydnaviruses into their hosts. These symbiotic viruses disrupt host immune responses, allowing the parasitoid's progeny to survive. Here we show that symbiotic polydnaviruses also have a downside to the parasitoid's progeny by initiating a multitrophic chain of interactions that reveals the parasitoid larvae to their enemies. These enemies are hyperparasitoids that use the parasitoid progeny as host for their own offspring. We found that the virus and venom injected by the parasitoid during oviposition, but not the parasitoid progeny itself, affected hyperparasitoid attraction toward plant volatiles induced by feeding of parasitized caterpillars. We identified activity of virus-related genes in the caterpillar salivary gland. Moreover, the virus affected the activity of elicitors of salivary origin that induce plant responses to caterpillar feeding. The changes in caterpillar saliva were critical in inducing plant volatiles that are used by hyperparasitoids to locate parasitized caterpillars. Our results show that symbiotic organisms may be key drivers of multitrophic ecological interactions. We anticipate that this phenomenon is widespread in nature, because of the abundance of symbiotic microorganisms across trophic levels in ecological communities. Their role should be more prominently integrated in community ecology to understand organization of natural and managed ecosystems, as well as adaptations of individual organisms that are part of these communities.

Ecological preferences, partner compatibility, or partner availability are known to be important factors shaping obligate and intimate lichen symbioses. We considered a complex of Cladonia species, traditionally differentiated by the extent of sexual reproduction and the type of vegetative propagules, to assess if the reproductive and dispersal strategies affect mycobiont-photobiont association patterns. In total 85 lichen thalli from 72 European localities were studied, two genetic markers for both Cladonia mycobionts and Asterochloris photobionts were analyzed. Variance partitioning analysis by multiple regression on distance matrices was performed to describe and partition variance in photobiont genetic diversity. Asexually reproducing Cladonia in our study were found to be strongly specific to their photobionts, associating with only two closely related Asterochloris species. In contrast, sexually reproducing lichens associated with seven unrelated Asterochloris lineages, thus being photobiont generalists. The reproductive mode had the largest explanatory power, explaining 44% of the total photobiont variability. Reproductive and dispersal strategies are the key factors shaping photobiont diversity in this group of Cladonia lichens. A strict photobiont specialisation observed in two studied species may steer both evolutionary flexibility and responses to ecological changes of these organisms, and considerably limit their distribution ranges.

Symbiosis plays a fundamental role in nature. Lichens are among the best known, globally distributed symbiotic systems whose ecology is shaped by the requirements of all symbionts forming the holobiont. The widespread lichen-forming fungal genus Stereocaulon provides a suitable model to study the ecology of microscopic green algal symbionts (i.e., phycobionts) within the lichen symbiosis. We analysed 282 Stereocaulon specimens, collected in diverse habitats worldwide, using the algal ITS rDNA and actin gene sequences and fungal ITS rDNA sequences. Phylogenetic analyses revealed a great diversity among the predominant phycobionts. The algal genus Asterochloris (Trebouxiophyceae) was recovered in most sampled thalli, but two additional genera, Vulcanochloris and Chloroidium, were also found. We used variation-partitioning analyses to investigate the effects of climatic conditions, substrate/habitat characteristic, spatial distribution and mycobionts on phycobiont distribution. Based on an analogy, we examined the effects of climate, substrate/habitat, spatial distribution and phycobionts on mycobiont distribution. According to our analyses, the distribution of phycobionts is primarily driven by mycobionts and vice versa. Specificity and selectivity of both partners, as well as their ecological requirements and the width of their niches, vary significantly among the species-level lineages. We demonstrated that species-level lineages, which accept more symbiotic partners, have wider climatic niches, overlapping with the niches of their partners. Furthermore, the survival of lichens on substrates with high concentrations of heavy metals appears to be supported by their association with toxicity-tolerant phycobionts. In general, low specificity towards phycobionts allows the host to associate with ecologically diversified algae, thereby broadening its ecological amplitude.

As self-supporting and long-living symbiotic structures, lichens provide a habitat for many other organisms beside the traditionally considered lichen symbionts-the myco- and the photobionts. The lichen-inhabiting fungi either develop diagnostic phenotypes or occur asymptomatically. Because the degree of specificity towards the lichen host is poorly known, we studied the diversity of these fungi among neighbouring lichens on rocks in an alpine habitat. Using a sequencing metabarcoding approach, we show that lichen mycobiomes clearly reflect the overlap of multiple ecological sets of taxa, which differ in their trophic association with lichen thalli. The lack of specificity to the lichen mycobiome is further supported by the lack of community structure observed using clustering and ordination methods. The communities encountered across samples largely result from the subsampling of a shared species pool, in which we identify three major ecological components: (i) a generalist environmental pool, (ii) a lichenicolous/endolichenic pool and (iii) a pool of transient species. These taxa majorly belong to the fungal classes Dothideomycetes, Eurotiomycetes and Tremellomycetes with close relatives in adjacent ecological niches. We found no significant evidence that the phenotypically recognized lichenicolous fungi influence the occurrence of the other asymptomatic fungi in the host thalli. We claim that lichens work as suboptimal habitats or as a complex spore and mycelium bank, which modulate and allow the regeneration of local fungal communities. By performing an approach that minimizes ambiguities in the taxonomic assignments of fungi, we present how lichen mycobiomes are also suitable targets for improving bioinformatic analyses of fungal metabarcoding.

Eilat Bay is located at the southernmost tip of Israel in the Gulf of Aqaba (Red Sea). The list of hydroids currently known from there includes 51 species, and when extending it to the entire Red Sea, it includes 157 species belonging to 41 families. Nevertheless, the information regarding hydroids in the Gulf of Aqaba, and in particular in Eilat Bay, is not exhaustive. The aim of this work is to improve knowledge of hydroid biodiversity in this area. The specimens collected during the HyDRa project (Hydroid Diversity of the Northern Red Sea) revealed the presence of 27 species, 13 Anthoathecata and 14 Leptothecata, belonging to 17 families and 20 genera. Two families, Cladonematidae and Corynidae, and five genera, Cladonema, Slabberia, Campanularia, Nemalecium and Lafoeina, are new findings for the Red Sea. Furthermore, Nemalecium lighti, Zanclea gallii and the new species Zanclea eilatensis sp. nov. have never before been recorded in the Red Sea. Zanclea eilatensis sp. nov. lives in association with a bryozoan, has a monomorphic colony lacking a perisarc and only has stenoteles in the polyps. The medusa stage has two prominent perradial exumbrellar nematocyst pouches and two tentacles with about 50 cnidophores having long flagella and containing macrobasic euryteles. In the present work, 54% of the species were associated with other organisms, such as hydroids, corals and bryozoans. New ecological data about the Zanclea–scleractinian coral association are documented. The present investigation provides new information about diversity in the Red Sea, and in particular in Eilat Bay. In addition, our data also have significance for Mediterranean and Red Sea biodiversity conservation due to the recent expansion of the Suez Canal and the consequent possible increase in the introduction of nonindigenous species in both directions. http://zoobank.org/urn:lsid:zoobank.org:pub:C9EA7333-B9DF-4888-A643-4D45E6CD31CB.

To date, four nominal species and several other unidentified species of Zanclea hydrozoans are known to live symbiotically with scleractinians, and recent surveys reported this association also in the Red Sea. Previous molecular studies showed that each coral genus involved in this association hosts only one species or molecular clade of Zanclea, with the only exception being the genus Acropora, which hosts at least two Zanclea species. Moreover, some of the detected genetic lineages were morphologically undistinguishable in the polyp stage, suggesting the presence of cryptic species. In this study, we investigated the morphology and genetic diversity of Acropora-associated Zanclea specimens collected in previous studies in Egypt and Israel, as well as new samples collected in Saudi Arabia. Based on the current data, all the analysed samples were morphologically identical to Zanclea gallii, a species associated with Acropora corals from the Maldives. However, molecular analyses separated the samples collected in the Red Sea from all other coral-associated hydroids. Therefore, phylogenetic reconstructions, haplotype networks, genetic distance analyses and distribution data allowed us to identify a previously unknown cryptic species of Acropora-associated hydroid, here named Zanclea gallii IIa, following a recently proposed molecular nomenclature.

Symbiotic scleractinian corals are particularly affected by climate change stress and respond by bleaching (losing their symbiotic dinoflagellate partners). Recently, the energetic status of corals is emerging as a particularly important factor that determines the corals’ vulnerability to heat stress. However, detailed studies of coral energetic that trace the flow of carbon from symbionts to host are still sparse. The present study thus investigates the impact of heat stress on the nutritional interactions between dinoflagellates and coral Stylophora pistillata maintained under auto- and heterotrophy. First, we demonstrated that the percentage of autotrophic carbon retained in the symbionts was significantly higher during heat stress than under non-stressful conditions, in both fed and unfed colonies. This higher photosynthate retention in symbionts translated into lower rates of carbon translocation, which required the coral host to use tissue energy reserves to sustain its respiratory needs. As calcification rates were positively correlated to carbon translocation, a significant decrease in skeletal growth was observed during heat stress. This study also provides evidence that heterotrophic nutrient supply enhances the re-establishment of normal nutritional exchanges between the two symbiotic partners in the coral S. pistillata, but it did not mitigate the effects of temperature stress on coral calcification.

The genome of about 10% of bacterial species is divided among two or more large chromosome-sized replicons. The contribution of each replicon to the microbial life cycle (for example, environmental adaptations and/or niche switching) remains unclear. Here we report a genome-scale metabolic model of the legume symbiont Sinorhizobium meliloti that is integrated with carbon utilization data for 1,500 genes with 192 carbon substrates. Growth of S. meliloti is modelled in three ecological niches (bulk soil, rhizosphere and nodule) with a focus on the role of each of its three replicons. We observe clear metabolic differences during growth in the tested ecological niches and an overall reprogramming following niche switching. In silico examination of the inferred fitness of gene deletion mutants suggests that secondary replicons evolved to fulfil a specialized function, particularly host-associated niche adaptation. Thus, genes on secondary replicons might potentially be manipulated to promote or suppress host interactions for biotechnological purposes., The genome of some bacteria consists of two or more chromosomes or replicons. Here, diCenzo et al. integrate genome-scale metabolic modelling and growth data from a collection of mutants of the plant symbiont Sinorhizobium meliloti to estimate the fitness contribution of each replicon in three environments.

International audience; In response to the presence of compatible rhizobium bacteria, legumes form symbiotic organs called nodules on their roots. These nodules house nitrogen-fixing bacteroids that are a differentiated form of the rhizobium bacteria. In some legumes, the bacteroid differentiation comprises a dramatic cell enlargement, polyploidization, and other morphological changes. Here, we demonstrate that a peptidoglycan-modifying enzyme in Bradyrhizobium strains, a DD-carboxypeptidase that contains a peptidoglycan-binding SPOR domain, is essential for normal bacteroid differentiation in Aeschynomene species. The corresponding mutants formed bacteroids that are malformed and hypertrophied. However, in soybean, a plant that does not induce morphological differentiation of its symbiont, the mutation does not affect the bacteroids. Remarkably, the mutation also leads to necrosis in a large fraction of the Aeschynomene nodules, indicating that a normally formed peptidoglycan layer is essential for avoiding the induction of plant immune responses by the invading bacteria. In addition to exopolysaccharides, capsular polysaccharides, and lipopolysaccharides, whose role during symbiosis is well defined, our work demonstrates an essential role in symbiosis for yet another rhizobial envelope component, the peptidoglycan layer.

Coral reefs are among the most biologically productive and diverse ecosystems in the world, representing hot spots of marine biodiversity, and directly sustaining half a billion people (Moberg and Folke 1999; Wilkinson 2004). Approximately 60% of coral reefs are currently threatened by several natural and anthropogenic impacts (Hughes et al. 2003; Pandolfi et al. 2003). Over the last 20 years, massive coral bleaching (i.e., loss of symbiotic zooxanthellae hosted within scleractinian corals) has increased dramatically, both in frequency and spatial extent (Hoegh-Guldberg 1999; Hughes et al. 2003; Knowlton 2001). This phenomenon has been associated with positive temperature anomalies, excess ultraviolet (UV) radiation or altered available photo-synthetic radiation, and presence of bacterial pathogens and pollutants (Brown et al. 2000; Bruno et al. 2007; Douglas 2003; Glynn 1996; Jones 2004). Production and consumption of personal care and cosmetic sun products are increasing worldwide, reaching unexpected levels, with potentially important consequences on environmental contamination. The release of these products is also linked with the rapid expansion of tourism in marine coastal areas (Wilkinson 2004). Chemical compounds contained in sunscreens and other personal care products have been demonstrated to reach detectable levels in both fresh and sea-water systems (Daughton and Ternes 1999; Giokas et al. 2007). These compounds are expected to be potentially harmful for the environment; hence, the use of sunscreen products is now banned in a few popular tourist destinations, for example, in marine ecoparks in Mexico, and in some semi-enclosed transitional systems (Xcaret 2007; Xel-ha 2007). Because sunscreens are lipophilic, their UV filters can bioaccumulate in aquatic animals (Giokas et al. 2007) and cause effects similar to those reported for other xenobiotic compounds (Balmer et al. 2005; Daughton and Ternes 1999). Paraben preservatives and some UV absorbers contained in sunscreens have estrogenic activity (Daughton and Ternes 1999; Schlumpf et al. 2004). In addition it has been demonstrated that several sunscreen agents may undergo photodegradation, resulting in the transformation of these agents into toxic by-products (Giokas et al. 2007, and literature therein). Recently, it has also been demonstrated that sunscreens have an impact on marine bacterioplankton (Danovaro and Corinaldesi 2003), but there is no scientific evidence for their impact on coral reefs. To evaluate the potential impact of sun-screen ingredients on hard corals and their symbiotic algae, we conducted several independent in situ studies with the addition of different concentrations of sunscreens to different species of Acropora (one of the most common hard-coral genus), Stylophora pistillata, and Millepora complanata. These studies were performed from 2003 to 2007 in different areas of the world, including the Celebes Sea (Pacific Ocean), the Caribbean Sea (Atlantic Ocean), and the Andaman Sea and the Red Sea (Indian Ocean).

Hydrozoans are able to establish intimate relationships with several other organisms. The hydroid Pteroclava krempfi lives in association with different alcyonacean taxa from Indo-Pacific and Atlantic coral reefs, growing partially embedded within host tissues. In this study, we found P. krempfi associated with four alcyonacean hosts from the Maldives, namely Sinularia, Sarcophyton, Lobophytum and Paraplexaura, the latter representing a new record. We provided the first molecular phylogenetic evaluation of the genus Pteroclava. Pteroclava krempfi clustered with Cladocoryne floccosa, confirming its position into the family Cladocorynidae. We also performed the first morpho-molecular assessment of P. krempfi diversity. All the colonies growing on different hosts revealed polyps and medusae matching published descriptions of P. krempfi, showing no morphological differences. However, analysing both nuclear and mitochondrial DNA, two highly supported molecular lineages were identified. These two clades were highly divergent and were specifically associated with hosts belonging to different families (Alcyoniidae and Plexauridae). Therefore, our results suggest that P. krempfi from the Maldives is a complex of cryptic species in which the main diagnostic feature between different species could be the host specificity.

The dynamics of symbiotic protist communities of Reticulitermes lucifugus ‘‘Sicily’’ were investigated to assess the effects of seasonal environmental conditions and the termite’s feeding activity. In worker and soldier castes, the total protist population (total abundance), individual species abundances, and species proportions in their hindguts were examined monthly from December 2012 to February 2014. The main protist species taken into account were Dinenympha fimbriata Kirby, D. gracilis Leidy, Pyrsonympha flagellata Gras., Spirotrichonympha flagellata Grassi u. Fo` a, Holomastigotes elongatum Grassi u. Fo`a, and Trichonympha agilis Leidy, while others were not specifically identified, but were counted together. Seasonal comparisons between worker and soldier castes were made. Further, monthly data of workers were examined. We always found the presence of symbiontic protists in worker and soldier hindguts, therefore we hypothesize that termites fed without periods of interruption. In both castes the total protist population and species abundance showed variable trends with the highest values in summer. Workers were found to have significantly larger populations of protists and abundances of individual species than soldiers. Similar protist species were observed in both castes and in all periods, except for H. elongatum which was sometimes absent in soldiers. In hindguts of workers and soldiers the proportions of the protist species often showed a significant variation across seasons except for S. flagellata and T. agilis. In both castes we always detected the highest percentage of Dinenympha spp. with respect to the other species. Elements that might influence these aspects are discussed.

Arbuscular mycorrhizal (AM) symbiosis is generally considered to be effective in ameliorating the plant tolerance to salt stress. Unfortunately, the comprehension of the mechanisms implicated in salinity stress alleviation by AM symbiosis is far from being complete. Thus, an experiment was performed by growing durum wheat (Triticum durum Desf.) plants under salt-stress conditions to evaluate the influence of AM symbiosis on both the plant growth and the regulation of a number of genes related to salt stress and nutrient uptake. Durum wheat plants were grown outdoors in pots in absence or in presence of salt stress and with or without AM fungi inoculation. The inoculum consisted of a mixture of spores of Rhizophagus irregularis (formerly Glomus intraradices) and Funneliformis mosseae (formerly G. mosseae). Results indicate that AM symbiosis can alleviate the detrimental effects of salt stress on the growth of durum wheat plants. In fact, under salt stress conditions mycorrhizal plants produced more aboveground and root biomass, had higher N uptake and aboveground N concentration, and showed greater stability of plasma membranes compared to non-mycorrhizal plants. Inoculation with AM fungi had no effect on the expression of the N transporter genes AMT1.1, AMT1.2, and NAR2.2, either under no-stress or salt stress conditions, probably due to the fact that plants were grown under optimal N conditions; on the contrary, NRT1.1 was always upregulated by AM symbiosis. Moreover, the level of expression of the drought stress-related genes AQP1, AQP4, PIP1, DREB5, and DHN15.3 observed in the mycorrhizal stressed plants was markedly lower than that observed in the non-mycorrhizal stressed plants and very close to that observed in the non-stressed plants. Our hypothesis is that, in the present study, AM symbiosis did not increase the plant tolerance to salt stress but instead generated a condition in which plants were subjected to a level of salt stress lower than that of non-mycorrhizal plants.

Although corals are known to host a variety of marine organisms, to date few benthic hydrozoans have been observed to be associated with anthozoans. However, three species belonging to the genus Zanclea have recently been discovered that inhabit reef-building scleractinians. Here we report the first evidence of such Zanclea-coral associations from the Red Sea, extending their known geographical distributions and host range.

Background Tomato (Solanum lycopersicum) establishes a beneficial symbiosis with arbuscular mycorrhizal (AM) fungi. The formation of the mycorrhizal association in the roots leads to plant-wide modulation of gene expression. To understand the systemic effect of the fungal symbiosis on the tomato fruit, we used RNA-Seq to perform global transcriptome profiling on Moneymaker tomato fruits at the turning ripening stage. Results Fruits were collected at 55 days after flowering, from plants colonized with Funneliformis mosseae and from control plants, which were fertilized to avoid responses related to nutrient deficiency. Transcriptome analysis identified 712 genes that are differentially expressed in fruits from mycorrhizal and control plants. Gene Ontology (GO) enrichment analysis of these genes showed 81 overrepresented functional GO classes. Up-regulated GO classes include photosynthesis, stress response, transport, amino acid synthesis and carbohydrate metabolism functions, suggesting a general impact of fungal symbiosis on primary metabolisms and, particularly, on mineral nutrition. Down-regulated GO classes include cell wall, metabolism and ethylene response pathways. Quantitative RT-PCR validated the RNA-Seq results for 12 genes out of 14 when tested at three fruit ripening stages, mature green, breaker and turning. Quantification of fruit nutraceutical and mineral contents produced values consistent with the expression changes observed by RNA-Seq analysis. Conclusions This RNA-Seq profiling produced a novel data set that explores the intersection of mycorrhization and fruit development. We found that the fruits of mycorrhizal plants show two transcriptomic “signatures”: genes characteristic of a climacteric fleshy fruit, and genes characteristic of mycorrhizal status, like phosphate and sulphate transporters. Moreover, mycorrhizal plants under low nutrient conditions produce fruits with a nutrient content similar to those from non-mycorrhizal plants under high nutrient conditions, indicating that AM fungi can help replace exogenous fertilizer for fruit crops.

Oreina cacaliae (Coleoptera: Chrysomelidae) is a rare example of viviparous insect, able to feed on toxic plants and sequester toxic compounds. Here we present the results of a study on the microbiota associated with O. cacaliae, based on 16S rRNA bacterial gene sequencing. Wolbachia resulted as the dominant bacterium, both in males (100%) and in females (91.9%). Based on multilocus sequence typing, the detected Wolbachia was described as a new sequence type (Wolbachia Ocac_A_wVdO). Phylogenetic analyses assigned Wolbachia Ocac_A_wVdO to supergroup-A. In situ hybridization and electron microscopy confirmed the presence of Wolbachia within O. cacaliae oocytes, indicating its transovarial transmission. PCR specific for Wolbachia was performed on representatives of six species of Oreina; the presence / absence of Wolbachia was then mapped on a cladogram representing the phylogeny of the insect host. Finally, since viviparous species of Oreina were either infected or non-infected by Wolbachia, we cannot derive any conclusion about the possibility that this symbiont played some role in the evolution of viviparity.

The contribution of this paper concerns how to extend the implementation of the approach of the Cultural Urban Landscape into the ‘regenerative city’ strategies: as it is possible to stimulate and to multiply the bonds and the circular relations, that is the circular virtuous processes, and then synergies, symbiosis and hybridization processes for the local development. The paper moves in the direction to contribute toward a new “urban science”, characterized by transdisciplinarity and hybridization. The landscape is a good example of issue that structurally requires a transdisciplinar approach. The hybridization is becoming a leitmotiv in the growth of globalization, creating a “third space” from which new plus-value arises.

Lichens that incorporate cyanobacterial symbionts (cyanolichens) are an ecologically key group of species used as biomonitors at all latitudes. Cyanolichen evolution is however based on intense studies of few keystone species and the bulk of species diversity, especially of small species in cold climates, has yet to be accounted for in phylogenetic studies. We assembled an expanded data set including members of all nine currently accepted Peltigeralean families as well as hitherto undersampled representatives of small, radially symmetrical, placodioid cyanolichen genera from the Northern and Southern Hemispheres. Bayesian and maximum likelihood consensus trees from our multilocus analyses (nuSSU, nuLSU and mtSSU) recovered the genera Koerberia, Vestergrenopsis and Steinera as a new, fully supported, family-level clade within the Peltigerales. This clade is further supported by a posteriori morphological analysis and we describe it here as the new family Koerberiaceae. The recently described and physiognomically similar genus Steineropsis, by contrast, is recovered as sister to Protopannaria in the Pannariaceae (Collematineae). Previous analyses have recovered strong monophyletic groups around Pannariaceae, Lobariaceae and Peltigeraceae. We discuss in detail the phylogenetic relationships of all these taxa, provide a pan-Peltigeralean overview of phenotypic characteristics and illustrate all major ascus apical structures. Our topology provides strong backbone support for the sister relationship of Peltigerineae to Collematineae as well as for most currently recognized families of the Peltigerales. The following new combinations are made: Steinera symptychia (Tuck.) T. Sprib. & Muggia, and Vestergrenopsis sonomensis (Tuck.) T. Sprib. & Muggia.

Here, we present an investigation on the spatial distribution of the bacterial symbiont Candidatus Midichloria mitochondrii within Ixodes ricinus, by whole mount fluorescence in situ hybridization (FISH). M. mitochondrii is a peculiar, recently discovered bacterium that resides in the mitochondria of female ticks. We applied a rapid and specific FISH protocol with oligonucleotide probes targeted on the 16S rRNA of M. mitochondrii, 12S rRNA of tick mitochondria, and a probe revealing active mitochondria. In this report that represents the first application of whole mount FISH on ticks, we observed strong, specific fluorescence signals in all the examined life stages, as the optimized protocol allowed us to overcome the autofluorescence interference of the cuticle. Cellular localization and quantification of the symbionts were also assessed with electron microscopy and specific real-time PCR, respectively.

Bactrocera oleae, fitofago chiave dell’agroecosistema olivo, è presente in Italia in tutti gli areali interessati dalla coltura, tranne in alcune aree caratterizzate da maggiore altitudine dove il fattore termico non consente lo sviluppo della specie. Il dittero è fortemente legato alle temperature che del resto condizionano anche la fenologia dell’olivo; in effetti il numero di generazioni che la mosca può completare nell’anno varia da 1 fino a 4-5 in zone con temperature medie annue elevate (zone costiere e/o meridionali). La pericolosità della specie è pertanto legata al numero di generazioni e all’andamento climatico che, a seconda dell’annata e della zona, possono variare sensibilmente condizionando la densità di popolazione e quindi il grado di dannosità potenziale del fitofago. Recenti ricerche sul comportamento e sulla biologia del tefritide hanno messo in evidenza come il fitofago, nel tempo, abbia contratto con i batteri una simbiosi mutualistica che permette al dittero di aumentare il proprio potenziale biotico. Nel presente articolo, dopo un breve excursus sulla biologia e sui danni causati dal fitofago, viene fatto il quadro delle attuali strategie di lotta ammesse nei protocolli dell’olivicoltura integrata e biologica. The control of the olive fruit fly in integrated and organic olive crops. Bactrocera oleae (Rossi) is the key pest of the olive agroecosystem; it is distributed in all Italian olive crops, except in some areas at higher altitude where low temperatures do not allow the development of the fly. The olive fruit fly development is strictly affected by temperature. It can complete from one up to five generations per year in areas with high annual average temperature (coastal and/ or southern areas). The harmfulness of the species is related to the number of generations and weather conditions which may fluctuate considerably year by year, region by region. Recent researches on behavior and natural history of the tephritid fly have pointed out that it has developed a mutualistic symbiosis with bacteria which allows an increase of its growth rate. In this article authors present control strategies permitted in integrated and organic olive crops. The currently widespread early harvesting and timely milling reduce the harmful influence of late olive fruit fly infestations; together with mass trapping and with repellent/ oviposition deterrent sprays by copper products and clays, these practices allow an increasingly sustainable effective control of the olive fruit fly

The evolution of plant–animal interactions goes back to the Early Archean, when the first signals of photosynthesis may have been detected in the Isua Peninsula in Greenland, a phenomenon that is related to the isotopic anomalies of carbon. The first evidence of reliable fossils of photosynthetic microorganisms has been identified by micropaleontologists in the Late Archean and Early Proterozoic. A closely related topic in this geologic time interval is the evolution of trophic relations and metabolic diversification in the microbial world. In the context of the three domains of life, Archea, Bacteria, and Eucarya, the bifurcation of multicellular organisms into plants and animals becomes evident only during the Paleozoic. Cell evolution also leads up to the unicellular dichotomy of autotrophs and heterotrophs. Symbiosis has a strong role to play in the transition to plants and animals in the Phanerozoic. It is timely to focus on the details of evolution in the Cretaceous and Tertiary, where detailed pathways of evolution have been gathered in many geographical regions, including the Karst region of northern Italy. Various experimental techniques have contributed to elucidate the coevolution of plants and animals. A special case of plant–animal interaction is the evolution and dispersal of hominins, including their impact on the ecosystems. A significant development in understanding the evolution of plant–animal interactions is based on the possibility of identifying reliable biomarkers that can characterize its different stages, from the earliest microbes to the extant plants and animals. Such identification of biomarkers labeling different stages of evolution may orient the search for life in the exploration of the Solar System.

Le simbiosi arbuscolo micorriziche (AM) sono formate dai funghi appartenenti al phylum Glomeromicota e piante superiori. Le simbiosi (AM) sono caratterizzate dalla penetrazione attiva del fungo dentro negli spazi intercellulari della cortaccia radicale e dalla formazione di strutture di scambio (chiamate ‘arbuscoli’) all’interno della parere cellulare. Gli arbuscoli sono strutture ramificate formate dal fungo AM all’interno della cellula vegetale invasa e sono indubbiamente gli organi chiave della simbiosi. Durante la loro formazione, la cellula vegetale si trasforma radicalmente. In particolare, la membrana cellulare si invagina e una membrana periarbuscolare con una ampia superficie di scambio tra pianta e fungo viene sintetizzata attorno all’arbuscolo e in continuo con la membrana cellulare stessa. Molti complessi enzimatici, soprattutto transporters, vengono sintetizzati dal fungo e dalla pianta sulla membrana periarbuscolari e sono responsabili di un intenso scambio di nutrienti e di segnali tra pianta e fungo. In continuum con la rete di ife intracellulari, il fungo AM forma una rete di ife extracellulari atte all’assorbimento di nutrienti dal suolo. Nella simbiosi AM vi è un trasporto netto di zuccheri dalla pianta verso il fungo e di nutrienti minerali dal fungo AM verso la pianta. La simbiosi comporta un costo energetico che va dal 4% al 20% del carbonio fissato dalla pianta, ma nel complesso non deprime lo sviluppo della pianta in quanto ne stimola l’attività fotosintetica. Lo stimolo della fotosintesi da parte della simbiosi AM è dovuto sia alla maggiore disponibilità di nutrienti, soprattutto quelli insolubili, per la pianta grazie all’attività di assorbimento delle ife extraradicali del fungo AM, sia a uno stimolo diretto del fungo sull’attività fotosintetica. Lo stimolo diretto dell’attività fotosintetica da parte dei funghi dipende probabilmente dalla loro attività di sink di carbonio nelle radici, ma pochi studi sono ancora stati fatti in materia. La maggiore disponibilità di nutrienti assorbiti dalla pianta micorrizica rispetto alla pianta non micorrizica dipende sostanzialmente da una migliore esplorazione del volume di suolo grazie alla presenza delle ife extraradicali. Le ife extraradicali del fungo AM presentano diverse caratteristiche che le rendono più idonee dei peli radicali nell’assorbire nutrienti. Le caratteristiche sono sostanzialmente tre: 1. dimensioni notevolmente più piccole dei peli radicali (ife: 3-7 μm di diametro; peli radicali più piccoli: 5-20 μm di diametro); 2. possibilità di assorbire nutrienti in forma non disponibili per la pianta (es: fosforo e azoto in forme organiche); 3. maggiore efficienza nell’assorbimento dei nutrienti rispetto alle radici Al momento, la maggior parte degli studi hanno evidenziato i maggiori assorbimenti di fosforo in piante micorrizate rispetto al controllo non micorrizico. Tale vantaggio si concretizza soprattutto quando la pianta cresce in condizioni di scarse disponibilità di fosforo (es: terreni poco dotati o con condizioni tali che ne determinano l’insolubilizzazione) o quando la pianta cresce sotto stress abiotici. Secondo alcuni autori (Schweiger & Jakobsen, 1998) in campo le micorrize sono responsabili dell’assorbimento della maggior parte del fosforo della pianta. La simbiosi micorrizica è inoltre efficiente nell’assorbimento di azoto dal suolo. In particolare, il fungo AM assorbe soprattutto ioni ammonio, ma anche nitrato e piccoli amminoacidi. In seguito il fungo AM trasloca azoto alla pianta sotto forma di ammonio. Infine la simbiosi AM può stimolare l’attività di mineralizzazione dell’azoto attraverso una stimolazione diretta dell’attività batterica nel suolo oppure modificando gli essudati escreti dalla pianta. La presente tesi è stata finalizzata a ottenere informazioni riguardo il contributo della simbiosi AM nell’alleviare l’effetto degli stress abiotici (idrici e nutrizionali) in colture mediterranee (Trifoglio alessandrino e grano duro) e saggiare l’importanza delle micorrize nell’incrementare le disponibilità di azoto per le piante attraverso uno stimolo dell’attività di N fixation o dell’attività di mineralizzazione dell’N organico nel suolo. In particolare sono stati effettuati due esperimenti: il primo in campo per testare l’effetto della simbiosi AM sulla crescita e sul processo di azotofissazione del trifoglio alessandrino durante il ricaccio e sottoposto a condizioni di scarsa o buona disponibilità idrica. Il secondo esperimento ha invece saggiato l’ipotesi che la simbiosi AM possa incrementare le disponibilità di N per la pianta ospite attraverso uno stimolo dell’attività di mineralizzazione dell’N organico. RISULTATI E DISCUSSIONE PRIMA PROVA La coltura (micorrizata e non micorrizata, split-plot con 4 repliche) è stata sottoposta a due sfalci (a 76 e 116 giorni dalla semina [gds]) e quindi sottoposta al trattamento “disponibilità idrica” (alta e bassa). Viste le scarsissime piogge dell’anno, soprattutto in primavera (pioggia primaverile inferiore del 55% rispetto alla media poliennale), la coltura con alte disponibilità idriche è stata irrigata con 90 mm di acqua a partire dal secondo taglio. A partire dal secondo taglio, la crescita della coltura è stata monitorata con cadenza settimanale per 4 settimane. Al primo taglio (76 gds), la coltura micorrizata ha accumulato una maggiore quantità di sostanza secca nella biomassa radicale, in quella aerea e ha presentato un maggior LAI rispetto alla coltura non micorrizata. Al secondo taglio (116 gds), nessun effetto è stato riscontrato per il trattamento “micorrizzazione”). A cominciare dal secondo taglio, la coltura è stata sottoposta a due regimi di disponibilità idrica e il ricaccio è stato monitorato settimanalmente. Inoltre la % di N fization è stata stimata a 14 e 28 giorni dal taglio (met. diluzione isotopica, L. multiflorum come coltura di riferimento trattata in maniera identica al trifoglio). Il fattore micorrizazione si è concretizzato in una maggiore produzione solo a 21 e 28 giorni dal secondo taglio. In quest’ultimo rilievo (28 gds), le micorrize hanno determinato una maggiore produzione solo nella coltura sottoposta a scarse disponibilità di acqua (idricamente stressata), mentre nessun effetto della micorriza è stato riscontrato nella coltura non stressata (alte disp. idriche). La maggiore produzione delle colture inoculate con micorrize è stata rilevata in campo da altri autori (Al Karaki et al., 2004). Nella presente prova, l’assenza di un effetto della micorrizza sulla crescita del trifoglio a 7 e 14 giorni dal secondo taglio potrebbe essere dovuta a una competizione per le sostanze di riserva tra i nuovi germogli della pianta e le micorrize. In questa fase, infatti, le piante mobilitano le riserve dal fittone e dalla corona verso i germogli (Ta et al., 1990; Ourry et al., 1994; Volenec et al., 1996; Avice et al., 1997; Meuriot et al., 2004), quindi riducendo al disponibilità di nutrienti per le micorrize che a loro volta non hanno stimolato la crescita della coltura. D’altra parte, a 21 e 28 giorni dal secondo taglio, quando la coltura ha già ricostituito l’apparato fotosintetizzante per soddisfare la domanda in zuccheri della micorriza, una maggiore crescita è stata osservata nella coltura micorrizata rispetto a quella non micorrizzata. A 14 giorni dal secondo taglio, nessun effetto della micorrizzazione è stato riscontrato sulla % e sulla quantità di N fissato dall’atmosfera, mentre a 28 giorni dal secondo taglio la micorrizzazione si è concretizzata in una maggiore quantità di N fissato solo nella coltura sottoposta a stress idrico. Risultati simili sono stati ottenuti da altri autori (Schoeneberger et al., 1989; Olesniewicz & Thomas, 1999; Goss & de Varennes, 2002; Antunes et al., 2006b) i quali, in moti casi, hanno attribuito il beneficio della simbiosi AM al processo di azotofizzazione alla migliore acquisiszione di fosforo nella pianta micorrizzata rispetto alla non micorrizata (Barea & Azcón, 1983). Inoltre Porcel et al. (2003) hanno osservato una maggiore attività della nitrogenasi nella soia AM rispetto alla soia non inoculata, con effetti più evidenti in condizioni di stress idrico. RISULTATI E DISCUSSIONE SECONDA PROVA La prova è stata effettuata in vaso. I trattamenti sono stati: micorrizzazione (+ G.mosseae; controllo non micorrizzato); aggiunta di sostanza organica (+ foglie di mais arricchite in 15N; + radici di mais arricchite in 15N; controllo senza aggiunta di sostanza organica). I trattamenti sono stati replicati 12 volte e l’analisi distruttiva delle piante (frumento duro cv. Simeto) è avvenuta a 7, 9 e 13 settimane di crescita. Negli stessi rilievi, l’attività enzimatica di degradazione dell’N organico nel suolo è stata misurata con i seguenti saggi: caseinasi (idrolisi di proteine in amminoacidi); BAA-proteasi e ureasi (idrolisi di amminoacidi in urea, si tratta di enzimi concorrenti); desidrogenasi (attività di respirazione totale dei batteri del suolo). Una soluzione nutritiva Hoagland modificata (10% N strenght e senza P) è stata applicata alla dose di 5 ml vaso-1 5 giorni-1. Una maggiore produzione (+15,6%) e N uptake (+15%) è stata osservata nella coltura AM rispetto alla coltura non micorrizzata. Ad ogni modo, nessun effetto della micorrizzazione è stato osservato sulla % di azoto delle piante. Altre ricerche hanno mostrato che l’effetto della simbiosi micorrizica sulla crescita del frumento è variabile (Al-Karaki & Al-Omoush, 2002; Li et al., 2005 and 2006) è può spaziare da un effetto depressivo a un effetto di forte stimolo. In generale, la simbiosi AM migliora l’N uptake del frumento in quanto accresce la capacità esplorativa e l’efficienza di assorbimento dell’N minerale (Miyasaka & Habte, 2001). Tale miglioramento è inoltre più evidente quando pianta e fungo AM non esplorano lo stesso volume di suolo (Hodge et al., 2001). La micorrizzazione ha praticamente dimezzato la % di azoto proveniente dalla sostanza organica e l’N recovery fraction del frumento. Al contempo, una maggiore attività di respirazione e proteolitica del suolo è stat osservata nella coltura micorrizzata rispetto al controllo non micorrizzato. In teoria, la maggiore attività proteolitica avrebbe dovuto implicare una più alta disponibilità di N proveniente dalla sostanza organica per le piante, il che avrebbe dovuto accrescere (e non diminuire) sia l’N recovery fraction che la % di N proveniente da SO. Anche Hodge et al. (2000b) ha osservato che una maggiore decomposizione dell’N organico nei trattamenti +AM rispetto al controllo –AM non era legata a un maggiore N recovery fraction. È possibile che nel sistema in esame, piante e microorganismi abbiano presentato una competizione differenziata per le diverse fonti di N: le piante micorrizzate sono state più efficienti nell’assorbire l’N minerale, mentre i batteri sono stati più efficienti nell’assorbire e metabolizzare l’N proveniente da sostanza organica. In tali condizioni, le piante micorrizzate hanno rapidamente esaurito le riserve minerali di N nel suolo e ciò ha stimolato i batteri a secernere enzimi proteolitici per far fronte alle proprie necessità di N. Di fatto, le proteasi batteriche sono enzimi inducibili secreti in relazione diretta al rapporto tra N organico e inorganico nel suolo (Gill & Modi, 1981; Chrost, 1991). Inoltre, nel breve periodo, i batteri sono più competitive delle piante a competere per l’azoto proveniente da SO (Nadelhoffer et al., 1985; Kaye & Hart, 1997; Hodge et al., 2000a) e quindi la riduzione dell’N recovery fraction può essere dovuta a un temporaneao sequestro dal sistema di N da SO organica da parte dei batteri. A conferma indiretta di questa ipotesi, Hodge (2003) ha osservato che dopo la raccolta, una più alta quantità di N mineralizzato dalla SO era presente nel suolo di piante micorrizzate rispetto a quello di piante non micorrizzate. CONCLUSIONI In entrambe le prove, la simbiosi micorrizzica è stata fondamentale nel determinare una maggiore crescita e accumulo di N in colture sottoposte a stress abiotici (idrici o nutrizionali). Nessun effetto è stato comunque riscontrato sulla concentrazione in N delle biomasse analizzate. Nella prova di campo, la simbiosi AM ha migliorato la produzione e il processo di N fixation solo in condizioni di stress idrico e non quando la coltura è stata allevata con alta disponibilità idrica. Negli ambienti mediterranei semiaridi, le colture autunno vernine soffrono spesso condizioni di siccità durante la fase finale del ciclo colturale, quindi nella scelta delle pratiche agronomiche da adottare, una particolare attenzione dovrebbe essere posta nell’effetto delle stesse sulla popolazione naturale di micorrize. Inoltre, l’inoculo del suolo con ceppi di funghi micorrizici efficienti nel ridurre gli stress idrici potrebbe essere una fruttuosa pratica agronomica nei nostri ambienti. Nella prova in vaso, la simbiosi ha determinato una maggior produzione, N uptake e una più alta attività enzimatica del suolo, la quale è direttamente correlata con la qualità del suolo stesso. La maggiore attività enzimatica, tuttavia, non ha presentato relazione con un cambiamento qualitativo della comunità microbiaca, il che suggerisce un effetto diretto delle micorrize sul processo di decomposizione dell’N organico.

In the last two centuries, native European oak forests have undergone a dramatic decline related to increasing human pressure for agriculture and urbanization. Oak forests were either completely eradicated and transformed into agricultural landscapes or replaced by second-growth formations. Intensive forest management and the replacement of native forests with production forests or arable lands are recognized amongst the main threats to many lichens in Europe. In this study, we used historical information on the epiphytic lichen biota which was hosted in a native oak-dominated forest of Northern Italy to identify shifts of lichen communities due to the changes in land use which occurred during the last two centuries. We also compared the epiphytic lichen communities inhabiting remnant oak forests with those found in the habitats that have replaced native forests: black-locust forests and agrarian landscapes. Almost all the species sampled during the 19th century are now extinct. The loss of native habitat and the subsequent invasion by black locust were probably the most influential factors which affected the composition of lichen communities, causing the local extinction of most of the species historically recorded. Despite the fact that oak remnants host only a few species which were historically recorded, and that they currently are the lichen poorest habitat in the study region, they host lichen assemblages differing from those of black-locust forests and agrarian stands. In these habitats lichen assemblages are mainly composed of species adapted to well-lit, dry conditions and tolerating air pollution and eutrophication. This pattern is likely to be common also in other lowland and hilly regions throughout Northern Italy where oak forests are targeted among the habitats of conservation concern at the European level. For this reason, a national strategy for biodiversity conservation and monitoring of lowlands forests should provide the framework for local restoration projects. © 2010 Elsevier B.V.

This chapter concentrates on the potential effects of transgenic cotton on the soil ecosystem of three major cotton growing areas in Vietnam: the coastal lowlands region, the central highlands (eastern and western Truong Son Mountain Range) and the south-eastern region. Soils in these three regions are very different, so it will be necessary to assess the effects of transgenic cotton on typical soils from all three regions. The soils in the south-eastern region are Luvisols, Andosols and Acrisols. In the central highlands, the soils are mainly Luvisols, Rhodic Ferrasols and Haplic Acrisols. The soils in the coastal lowlands region are mainly delta soils, consolidated occasionally by grey light soils.

Scleractinian reef corals have recently been acknowledged as the most numerous host group found in association with hydroids belonging to the Zanclea genus. However, knowledge of the molecular phylogenetic relationships among Zanclea species associated with scleractinians is just beginning. This study, using the nuclear 28S rDNA region and the fast-evolving mitochondrial 16S rRNA and COI genes, provides the most comprehensive phylogenetic reconstruction of the genus Zanclea with a particular focus on the genetic diversity among Zanclea specimens associated with 13 scleractinian genera. The monophyly of Zanclea associated with scleractinians was strongly supported in all nuclear and mitochondrial phylogenetic reconstructions. Furthermore, a combined mitochondrial 16S and COI phylogenetic tree revealed a multitude of hidden molecular lineages within this group (Clades I, II, III, V, VI, VII, and VIII), suggesting the existence of both host-generalist and genus-specific lineages of Zanclea associated with scleractinians. In addition to Z. gallii living in association with the genus Acropora, we discovered four well-supported lineages (Clades I, II, III, and VII), each one forming a strict association with a single scleractinian genus, including sequences of Zanclea associated with Montipora from two geographically separated areas (Maldives and Taiwan). Two host-generalist Zanclea lineages were also observed, and one of them was formed by Zanclea specimens symbiotic with seven scleractinian genera (Clade VIII). We also found that the COI gene allows the recognition of separated hidden lineages in agreement with the commonly recommended mitochondrial 16S as a DNA barcoding gene for Hydrozoa and shows reasonable potential for phylogenetic and evolutionary analyses in the genus Zanclea. Finally, as no DNA sequences are available for the majority of the nominal Zanclea species known, we note that they will be necessary to elucidate the diversity of the Zanclea-scleractinian association.

The mosquito Aedes albopictusi is a competent vector of harmful human pathogens, including viruses causing dengue and chikungunya. Cytoplasmic incompatibility (CI) induced by endosymbiotic Wolbachia can be used to produce functionally sterile males that can be released in the field as a suppression tool against this mosquito. Because the available sexing methods are not efficient enough to avoid unintentional release of a few transinfected females, we assessed the CI pattern in crosses between wPip Wolbachia-transinfected (ARwP) females and wild-type males of Ae. albopictus in this study. Quantitative polymerase chain reaction was used to monitor the titer of the Wolbachia strains that naturally infect Ae. albopictus, that is, wAlbA and w AlbB, in age-controlled males and females. Data were coupled with incompatibility level detected when the above-mentioned males were crossed with ARwP females. Wolbachia infection titer was also monitored in samples of wild caught males. Incompatibility level was positively correlated only with wAlbA density. Crosses between wild-type males having very low wAlbA density (

The bacterial communities associated with 11 different lichen samples (belonging to eight different species) from different habitats were investigated. The culturable aerobic-heterotrophic fraction of the bacterial communities was isolated from nine lichen samples on protein-rich and sugar-rich/N-free media. Thirty-four bacterial isolates were purified and pooled into groups (phylotypes) by analysis of the ribosomal internal transcribed spacer polymorphism. Twenty five phylotypes were identified, each comprising between one and three isolates. One isolate of each phylotype was partially sequenced and the resulting 16S rRNA gene sequences were compared in a phylogenetic analysis. Three genera of Firmicutes, four of Actinobacteria and three of Proteobacteria were identified. Two phylotypes, belonging to the phyla Actinobacteria and Proteobacteria, respectively, were not identified at genus level. Some bacterial taxa were retrieved frequently in different lichen species sampled in the same or different sites. Paenibacillus and Burkholderia phylotypes seem to be common in lichens. Luteibactor rhizovicina was found in three different lichens of two different regions. In a cultivation-independent approach, total DNA was extracted from 11 lichen samples. Molecular fingerprints of the bacterial communities were obtained by PCR-amplification of the internal transcribed spacer region, and sequencing of selected bands indicated the presence of additional bacteria.